In a radio communication system that covers a communication area by cells made up by radio base stations, communication among radio terminals over a wide range is made possible by the arrangement of a plurality of cells. In WiMAX (Worldwide Interoperability for Microwave Access), for example, communication is made possible in a variety of locations by covering communication areas by small-scale cells referred to as femtocells. In this type of radio communication system, there exists one form of communication in which the data of programs are broadcast to a plurality of radio terminals (see JP2005-516474A and JP2007-174645A).
The data of programs are broadcast by radio channels set within bands that can be used by the radio communication system. Users can view programs by using radio terminals to receive the data of radio channels by which the programs are broadcast. Typical radio terminals for viewing this type of broadcast include stationary terminals as represented by radios or televisions for home use or portable terminals that can be transported.
However, radio resources are limited in a radio communication system. In addition, radio bands that can be used for broadcasting programs are further limited because radio channels are also used in point-to-point communication.
A state in which there are insufficient radio bands available for use to broadcast programs can occur regardless of the number of programs to be broadcast. For example, when there are ten programs and a radio band of 1 MHz is required for broadcasting a single program, a band of 10 MHz is required to broadcast all of the programs. However, cases can actually occur in which a radio band of only 3 MHz is available. In such states, it is difficult to decide how programs can be broadcast.
A technique is disclosed in JP2001-313922A (paragraphs 0023-0024) in which the users' inclinations are considered in the selection of programs to be broadcast. However, this technique does not reflect users' inclinations in real time when selecting programs to be broadcast. In addition, a particular program may not be broadcast at all if viewing requests for that program are fewer than other programs. The undesirable situation may therefore occur in which a program desired by users cannot be viewed at all even when there are users who wish to view the program.
JP2003-333571A discloses a technique in which the details of the content or users' preferences are considered in compressing content data that are to be distributed in a network. In addition, JP2002-351438A discloses a technique for controlling the image size, picture quality, and frame rate of image information that is distributed. However, the constructions disclosed in these documents do not take into consideration 1:N broadcast.
Although radio communication systems have here been mentioned by way of example, the broadcast of program data is carried out similarly in a wired communication system. The limitation of communication resources also applies to wired communication systems.